In the title compound, [Lu(2)(C(8)H(4)O(4))(2)(C(2)O(4))(H(2)O)(2)](n), the Lu(3+) cations are each coordinated by eight O atoms of four terephthalate anions, one oxalate anion and one aqua ligand to complete a distorted square-anti-prismatic geometry. They are bridged by the terephthalate ligands, generating a three-dimensional framework, which is further stabilized by the oxalate ligands. The terephthalate ions and oxalate ions are all located on centers of inversion.